Stresses in a Spherical Shell With a Circular Elastic Inclusion

1974 ◽  
Vol 96 (3) ◽  
pp. 228-233
Author(s):  
P. Prakash ◽  
K. P. Rao
Keyword(s):  
Differential Equations ◽  
Spherical Shell ◽  
Elastic Inclusion ◽  
Circular Inclusion ◽  
Shallow Spherical Shell ◽  
Spherical Shells ◽  
Hankel Functions ◽  
Circular Elastic Inclusion ◽  
Rigid Circular Inclusion

The problem of a circular elastic inclusion in a thin pressurized spherical shell is considered. Using Reissner’s differential equations governing the behavior of a thin shallow spherical shell, the solutions for the two regions are obtained in terms of Bessel and Hankel functions. Particular cases of a rigid circular inclusion free to move with the shell and a clamped rigid circular inclusion are also considered. Results are presented in nondimensional form which will greatly facilitate their use in the design of spherical shells containing a rigid or an elastic inclusion.

Pressurized Cylindrical Shell With a Rigid Circular Inclusion

1978 ◽  
Vol 100 (2) ◽  
pp. 158-163 ◽  
Author(s):  
D. H. Bonde ◽  
K. P. Rao
Keyword(s):  
Differential Equation ◽  
Cylindrical Shell ◽  
Shallow Shell ◽  
Circular Inclusion ◽  
Hankel Functions ◽  
Curvature Parameter ◽  
Shell Equations ◽  
Limiting Case ◽  
Rigid Circular Inclusion ◽  
Good Agreement

The effect of a rigid circular inclusion on stresses in a cylindrical shell subjected to internal pressure has been studied. The two linear shallow shell equations governing the behavior of a cylindrical shell are converted into a single differential equation involving a curvature parameter and a potential function in nondimensionalized form. The solution in terms of Hankel functions is used to find membrane and bending stressses. Boundary conditions at the inclusion shell junction are expressed in a simple form involving the in-plane strains and change of curvature. Good agreement has been obtained for the limiting case of a flat plate. The shell results are plotted in nondimensional form for ready use.

Nonlinear Stability Analysis of the Vaulted Roofs With Corrosion Defects of Oil Storage Tank

2009 ◽  
Author(s):  
Baosheng Dong ◽  
Xinwei Zhao ◽  
Hongda Chen ◽  
Jinheng Luo ◽  
Zhixin Chen ◽  
...  
Keyword(s):  
Spherical Shell ◽  
Nonlinear Stability ◽  
Storage Tank ◽  
Critical Pressure ◽  
External Pressure ◽  
Shallow Spherical Shell ◽  
Nonlinear Stability Analysis ◽  
Spherical Shells ◽  
Oil Storage ◽  
Oil Storage Tank

The vaulted roofs of oil storage tank are usually designed as the shallow spherical shells subjecting to a uniform external pressure, which have been widely observed that these shallow spherical shells undergo various levels of corrosion in their employing conditions. It is important to assess the stability of these local weaken shallow spherical roofs due to corrosion for preventing them from occurring unexpected buckling failure. In this paper, the uniform eroded part of a shallow spherical oil tank vaulted roof is simplified as a shallow spherical shell with elastic supports. Based on the simplification, a general pathway to calculate the critical pressure of eroded shallow spherical shell is proposed. The modified iteration method considering large deflection of the shell is applied to solve the problem of nonlinear stability of the shallow spherical shells, and then the second-order approximate analytical solution is obtained. The critical pressure calculated by this method is consistent with the classical numerical results and nonlinear finite element method, and the calculation errors are less than 10%. It shows that it is feasible to apply the method proposed here.

Nonlinear Dynamic Response and Active Control of Piezoelastic Laminated Shallow Spherical Shells with Damage

2011 ◽  
Vol 21 (6) ◽  
pp. 783-809 ◽  
Author(s):  
Mao Yiqi ◽  
Fu Yiming ◽  
Tian Yanping
Keyword(s):  
Dynamic Response ◽  
Spherical Shell ◽  
Vibration Control ◽  
Analytical Model ◽  
Constitutive Relations ◽  
Collocation Point ◽  
Shallow Spherical Shell ◽  
Geometrical Parameters ◽  
Orthogonal Collocation ◽  
Spherical Shells

Based on Talreja’s damage model with tensor valued internal state variables and geometric nonlinear theory, the constitutive relations for a moderately thick shallow spherical shell with damage are derived. The distribution of electric potential along the thickness direction in the piezoelectric layer is simulated by a sinusoidal function, and accordingly the dynamic analytical model for the cross-ply laminated moderately thick piezoelectric shallow spherical shell is established. Using the negative velocity feedback control algorithm, an analytical model for active vibration control of the piezoelectric laminated moderately thick piezoelectric shallow spherical shell is built when the damage effect is considered. And the solutions to the whole problem are obtained with synthetical utilization of the orthogonal collocation point method and the Newark method. In numerical examples, the effects of damage, piezoelectric effect, and the structure’s geometrical parameters on the dynamic response and vibration control of the piezoelastic laminated shallow spherical shells with damage are investigated.

Application of the Point-Matching Method to Shallow-Spherical-Shell Theory

1962 ◽  
Vol 29 (4) ◽  
pp. 745-747 ◽  
Author(s):  
H. D. Conway ◽  
A. W. Leissa
Keyword(s):  
Spherical Shell ◽  
Shell Theory ◽  
Shallow Spherical Shell ◽  
Circular Pipe ◽  
Radial Load ◽  
Matching Method ◽  
Spherical Shells ◽  
Point Matching ◽  
Circular Base

Using Reissner’s [1] theory of the bending of shallow spherical shells, two unsymmetrical problems are investigated by the method of point-matching. The first is a uniformly loaded spherical shell clamped on a square base, numerical values of the moments and membrane forces being obtained and compared with the corresponding values for the case of a clamped circular base. The second problem is a spherical shell with a rigid elliptical insert, the latter carrying a central radial load. This gives information concerning the problem of a spherical shell which is pierced at an angle by a relatively rigid circular pipe.

On the Influence of a Rigid Circular Inclusion on the Twisting and Shearing of a Shallow Spherical Shell

1980 ◽  
Vol 47 (3) ◽  
pp. 586-588 ◽  
Author(s):  
E. Reissner
Keyword(s):  
Near Field ◽  
Circular Inclusion ◽  
Interior Solution ◽  
Far Field ◽  
Stress Concentrations ◽  
Spherical Shells ◽  
Edge Zone ◽  
Field Behavior ◽  
Membrane Type ◽  
Rigid Circular Inclusion

Known results for plates with rigid inclusions are complemented by explicit asymptotic solutions of the corresponding problems for sufficiently thin spherical shells. An important element of the analysis is recognition of the fact that in addition to the distinction between interior and edge zone solution contributions there is a significant distinction between near-field and far-field behavior of the interior solution, with the nature of this distinction depending on the nature of the boundary conditions which are prescribed. In the event that near-field behavior is of the membrane type and far-field behavior of the inextensional bending type, or vice versa, much higher stress concentrations occur than without such change in interior solution behavior.

A Comparison of Theoretical and Experimental Results From Spherical Shells With a Single Radially Attached Nozzle

1967 ◽  
Vol 89 (3) ◽  
pp. 333-338 ◽  
Author(s):  
F. J. Witt ◽  
R. C. Gwaltney ◽  
R. L. Maxwell ◽  
R. W. Holland
Keyword(s):  
Spherical Shell ◽  
Internal Pressure ◽  
Experimental Results ◽  
Strain Gages ◽  
Spherical Shells ◽  
Axial Thrust ◽  
Outside Diameter ◽  
Theoretical Results

A series of steel models having single nozzles radially and nonradially attached to a spherical shell is presently being examined by means of strain gages. Parameters being studied are nozzle dimensions, length of internal nozzle protrusions, and angles of attachment. The loads are internal pressure and axial thrust and moment loadings on the nozzle. This paper presents both experimental and theoretical results from six of the configurations having radially attached nozzles for which the sphere dimensions are equal and the outside diameter of the attached nozzle is constant. In some instances the nozzle protrudes through the vessel.

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